Here's the criteria that the score is build on.

From a quick glance, I'd say US is majorly lacking in:

• Equal opportunity to participate, vote: from felons bring denied voting rights to gerrymandering to Wisconsin votes being worth 4 times as much as California votes in presidential elections die to the EC, there's a lot of fundamental issues here
• Independence of the judiciary: the supreme court is not independent, and presidential pardons are a mockery of any justice system

What do you mean what's the catch?

Looking at the list, less a catch more a difference of ethos. Higher taxes for better public services and more even wealth distribution for social cohesion.

Many are less diverse than the USA, which brings pros and cons too.

Do you mean "okay, but why is it still better to live on America than those places?" The answer to that one is, for the most part, it's not. (I have lived a fairly sketchy life but the three times I've had guns drawn on me have all been in my brief visits to America.)

Do you mean, how are they more democratic? Gerrymandering, unlimited campaign contributions to "PAC" which are absolutely totally not working with parties and of course, the obscenely impressive ways pork gets stuffed into the most innocuous of bills by design all come leaping to mind.

In the US there are 2 political parties

In Denmark theres many more. The current government is 3 parties, and theres a total of 13 iirc, currently elected parties.

You can (most likely) find a political party to represent you.

Democracy in the US hasn't been in a worse state in a very long time. There's not much of a trick to having a stronger democracy than that...

Why should there be a catch?

Speaking for NZ, while we do have things like:

Cheap or free healthcare

Roads in good condition

Low corruption/Limited power

Excellent conservation

Great public services

High level of safety

Very strong employment laws

Very low exploitation

Very open press

Free speech

Almost nearly adequate climate policies

We are still stuck with a lot of people who have the red vs blue mindset. People often vote for the party that is most likely to stop the party they don't want getting in to power.

We have MMP here, which is of course the best system, we have political parties across the spectrum so that the largest amount of people have representation. But goddam it's always the same 2 in majority power.

There's delay in progressive change, eg decriminalizing weed, providing better health services.

When the wrong party is in (team blue) they focus on the wrong things ie building even more roads instead of improving public transport etc.

When the less wrong party is in (team red) they focus on appearing to do things that we care about but do a bad job.

It's difficult to nail down general specifics but I think you get the idea.

That list seems mostly right, however...

The UK, France and Spain ARE NOT working democracies.

They can be considered "functioning" goverments to a degree, (and great economies no doubt).

But those 3 countries have deep socio-political issues that their goverments should attent with outmost urgency.

I don't think i should describe the situation in France, as it has been spoken quite frequently in recent months.

In the case of UK and Spain, large fractions of their populations (Ireland, Scotland and Cataluña) do not feel a partriotic sentiment towards their country as a whole, but rather the region they live in, and consider that said region should be divided into an independent nation.

Before you dive into the negative aspects (and possible concequences) of such a division, let me remind you of the current conflict between Russia and Ucraine. In wich, Russia (or more accurately the Russian goverment) wants to claim Ucraine back as part of their territory despite most people in both countries being against that decision (and even more so about the idea of a war to resolve said conflict).

Back to the UK and Spain, inside those countries, elections have been held to decide if their regions should split and be independent. However, said elections weren't quite "fair" as most people in the regions that wanted to be independent did vote on favor of independence, however it was the mayority of the countries' populations (England and the rest of Spain), that voted to keep things as they are.

AKA People that don't live (and probably don't even interact with said regions) took the decision FOR THEM.

This is specially frustrating in the case of Cataluña because they speak AN ENTIRELY DIFFERENT LANGUAGE from the rest of Spain.

So in conclusion, i believe that for those 3 countries to be considered "working democracies" their goverments should focus on the true needs of their people, rather than deciding matters on economic factors.

The catch is that more democracy is not guaranteed to result in better government. But less democracy has way worse side effects.

With a few exceptions, I’d rather be a random citizen in any of the countries on your list than in the US.

What is this score based on? I had a quick skim of their site but my eyes kinda glazed over, polsci isn't my background. Can someone ELI5?

Events in the UK, specifically tightening protest restrictions after Lizzy died and JK Rowling silencing critics through legal threats (just so you know, Trump wanted the US's libel laws to be more like the UK's but it never happened,) solidified my opinion that the first amendment is a net good.

I would maybe put Israel below the US based on what I know (since these kind of rankings are shaky) but that's about the only thing I genuinely think the US does best on a governmental level.

Some of my (uneducated) guesses:

• they're also wellfare state, so they're tight when it comes to immigration
• similar in terms of culture, making it easier for them to agree on which policies to follow. So there may or may not be xenophobia

I wouldn't really call it a "catch", but these kinds of indexes are heavily colored by the political persuasion of those creating the metrics by which the index judges. For instance, they judge various social inequalities as being a "worse democracy", which you may or may not agree with.